Idle, Fuel mixture questions
#1
Idle, Fuel mixture questions
Hi,
I started thinking about the mixture adjustment and I think I've been making my AFM adjustments backwards.
Regarding the idle and mixture adjustments; here's what I now believe to be correct. Please let me know if / where I'm off.
The fuel rich/lean mixture is adjusted by turning the screw on the AFM. This passage bypasses the AFM flap. Clockwise rotation of this screw closes off this passage and counter-clockwise rotation opens the passage. Opening this passage allows more air into the engine without the AFM knowing about it and therefore leans the mixture.
The Idle speed is set by adjusting the screw in the air distribution block. This passage bypasses the throttle plate. Clockwise rotation of this screw closes the passage and reduces air flow to the engine counterclockwise rotation of this screw opens the passage and allows more air into the engine and the idle rises.
Does this Idle adjustment passage draw its air from the post-AFM intake? I assume that it does, otherwise this adjustment would also lean the mixture.
Thanks,
Paul
I started thinking about the mixture adjustment and I think I've been making my AFM adjustments backwards.
Regarding the idle and mixture adjustments; here's what I now believe to be correct. Please let me know if / where I'm off.
The fuel rich/lean mixture is adjusted by turning the screw on the AFM. This passage bypasses the AFM flap. Clockwise rotation of this screw closes off this passage and counter-clockwise rotation opens the passage. Opening this passage allows more air into the engine without the AFM knowing about it and therefore leans the mixture.
The Idle speed is set by adjusting the screw in the air distribution block. This passage bypasses the throttle plate. Clockwise rotation of this screw closes the passage and reduces air flow to the engine counterclockwise rotation of this screw opens the passage and allows more air into the engine and the idle rises.
Does this Idle adjustment passage draw its air from the post-AFM intake? I assume that it does, otherwise this adjustment would also lean the mixture.
Thanks,
Paul
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